Saprolegnia megasperma

Saprolegnia megasperma Coker, Saproleg. 56. 1923
Hyphae on mushroom-grubs or termites, 9-35 fx thick, most of them about 15-20 n thick, reaching a length of 0.5-0.7 cm., straight to wavy; sporangia abundant on most media, apical, 15-45 by 100-400 ju, variable in shape, the first ones usually long and distinctly swollen at the distal end, the later ones usually smaller and more or less irregular in outline, renewed by internal proliferation or rarely by cymose branching (in cultures slightly infected with bacteria the sporangia may break away from the threads as in Dictyuchus, such sporangia emptying normally after a long or short rest) ; spores 1 1 ix thick when encysted; gemmae abundant, round to oval or very irregular, emptying upon the addition of fresh water by one or more long papillae; oogonia produced in fair abundance, usually borne on short racemose branches generally less than the diameter of the oogonia, not rarely borne singly or in clusters of several on the ends of the main threads when sporangia are sparingly produced, 40-100 /z in diameter, the wall smooth (rarely with a papilla), not thick, without pits or rarely with a few small ones; eggs 1-10, single in more than half of the oogonia in most cultures, 30-52 y. in diameter, usually about 38 ju, subcentric (one row of oil-droplets on one side, two on the other), not filling the oogonia; antheridia present on all oogonia, applied by their ends, seldom by their sides; antheridial walls thick, easily visible even in old cultures; antheridial branches usually of androgynous origin but quite often diclinous, usually simple and unbranched; antheridial tubes developed and easily visible.
Typ£ locality: Wilmington, North Carolina. Habitat: Fresh water and soil. Distribution: North Carolina; also in Kurope.